When designing and redecorating churches, special care must be made to govern the eyes of the people, directing the the viewer in helpful directions conducive to divine worship. If this is not achieved, the viewer may find himself disoriented, unfocused, or worse disturbed and confused. Focal spots are those areas where the viewer is directed to look more immanently, more frequently and with greater interest. Principles for controlling these focal spots are well known. Primarily, focal spots are caused by geometry and color. These causes are 10 in number: position, convergence, orientation, predominance, shape, texture, anomalousness, hue, brightness, and vibrancy,
Position
Position is the most chief of these causes, where the location of a thing dictates its strength as a focal spot. This can can achieved in various ways, the most simple being that the areas intended as a focal spot will be placed front and center, perhaps somewhat high if in an architectural space, to ensure it can be easily viewed by all in an obvious way. Alternatively, the intended focal spot or spots may be somewhat isolated from other components or items so that it can be made to be easily noticeable and distinct.
See this icon of 'The Good Shepherd' where the eye effortlessly finds interest in the one lost sheep in the arms of Christ over the other sheep despite the fact that it is somewhat smaller and has no notable markings or distinguishing features. The lost sheep is placed prominently near the center of the image and separated from the others by the body of Christ' garments. This icon is working as intended, placing the focal point on the lost sheep so to guide meditation in a helpful way.
Convergence:
Another powerful effect often employed in religious architecture is that of convergence. This is where a system of lines is set up so that as the eye wanders the view and begins to follow the lines of the composition, it is lead to a common focal spot. In Owen Jones' Grammar of Ornament he hints at this tool under proposition number 11 where he says,
"In surface decorations all lines should flow out of a parent stem. Every ornament however distant should be traced to its root and branch."
Such geometric systems intersecting and undulating lines can become very complex. In its essential form, lines direct focus to a given spot without disjointing that spot from the whole view. The spot is of visual interest because the surrounding area points toward it.
Often seen in retablo niche clamshells such as these of San Juan de los Santos at the San Agustin Museum Manila Philippines, each niche draws the interest of the eye from a local area and drops the eye into a focal spot at the face of each saint. The overall composition is very busy and complex, easy to get lost in, but focus is directed toward the important bits. Thus able to locate each saint more easily, pious behavior in the faithful can be facilitated.
Orientation:
Perhaps not obviously, orientation as a vehicle for locating a focal point has an important role especially when involving the bodies of persons. In its simplest form, switching the orientation of an object within a field of like objects creates what is call visual pop-out. This takes on added weight and meaning when involving persons, because the orientation of a person in artistic scenes and religious ceremonies often is also an indicator of the person's role and actions.
As a simple case study, see the common depiction of the 42 negative confessions in the Egyptian Book of the Dead. Here 42 gods sit in judgement against the deceased whom swears he has not committed 42 specific sins, one to each god. Due to orientation, it is obvious which person is the deceased; the viewer finds paying attention to that person despite that he is perhaps otherwise the least visually interesting, dressed in a simple white tunic and with only the most generic Egyptian features. The gods themselves are far more interesting, each with odd colors and some with grotesque animal features, yet it is almost hard to focus on any of them individually.
Further, one can see this principle at play in Catholic churches by comparing 'ad orientem' with 'versus populum' liturgical arrangements. In 'ad orientem' liturgies, the priest shares the orientation of the congregation and the servers, focusing all attention on the heavenly artistic figures of the church, the Crucifix, retablo, murals, et cetera. In this form, according to Gestalt principles, the priest is made to seem in union with the people in the church's offering to God.
In 'versus populum' liturgies, the priest stands facing the people and the servers with his back to the crucifix and other the figures, thus reorganizing the focus of the congregation. In this form, the priest is made to be associated more with the religious statuary and paintings and thus is of greater focus in a clericalist way. Despite strong opinions to the contrary, aesthetically speaking, facing the people cause the priest to be in less perceived union with the congregation. All things are significant and done for a reason.
Predominance:
More commonly used, one will see the principle of predominance. Really as simple as making the thing worthy of focus bigger, when one or a small number of objects standing significantly larger than the rest, greater focus is allocated to the proverbial the elephant in room. This was widely, almost universally practiced by everyone before the modern age. Against our sensibilities, the most important figure of an illustrated textile, carving, or drawing was made the biggest, even if at a non-realistic scale.
See how this portion of the Bayeux Tapestry has no respect for a literal scale where figures are strictly graded in size according to their importance. There stands no confusion whatsoever in this small textile (only about 20 inches tall) what the important parts of the story to the reader ought to be. The scene is expertly grade showing hierarchy of information, firstly the large unnamed messenger is bringing news of Harold invading England to the slightly less important King William, and in the next frame soldiers are shown burning still smaller Saxon homes. In the last degree is shown displaced women and children, the child no taller than the messenger knee. The sequence of information directly follows the hierarchy of size.
Not contained to merely two dimensional images; this is often seen even in modern churches with statues of Jesus and Mary standing somewhat taller than minor saints in nearby niches of the same plane such as in the retablo seen previously. This can be even more dramatically seen in the arrangement of the Batu Caves complex in Malaysia. The entry plaza is dominated by a 140 foot tall gilded concrete statue of the Hindu idol Murugan. This is despite him being less visually interesting than the frantic busyness and wrenchingly vibrant color of his surroundings. If the Hindu war god was even only 50 foot tall it might be lost in the disorienting sea of color and churning deities and his subjugation over the complex less felt.
Shape:
Perhaps as one of the least recognized but most basic and most employed causes is that of the principle of shape. Most easily observed in purely natural phenomenon, the human eye is deeply programmed at a natural level to recognize and focus on contrasts in shape. Whether the coil of a snake or the roundness of a fruit, the eye knows that contrasts of shape often relay important information. This principle often comes into public awareness from practices in landscaping and floristry. Potted plants often possess an internal order where draping vines are at the sides, bushy plants make up the bulk, and a central spike acts as a visual spine. Floral bouquets have similar systems of arrangement. Here we see such a spike arrangement where the spike by contrast of shape from the other scrubby plants allows the eye to establish the planers as a unit of focus instead of a nebulous unitless blob. Perhaps also utilizing principles of convergence, directing lines toward pot, the spike is so different in shape from the mossy surrounds that it becomes a focal point.
Texture:
Texture is yet another causative principle of focus that extremely prevalent but perhaps is more obscure. Taking many forms, this texture essentially is contrast of detail density whereby an area becomes a focal spot because it is notably more or less visually interesting.
The Golden Throne of Tutankhamun demonstrates this principle where the smooth inlaid stones and enamels are so different from the intense detail density and shimmering gold that they becomes the area of greatest focus. Usually this is seen in the reserve where the areas of suddenly greater detail are the spots of focus. This reserve, the conventional application of this principle, follows Owen Jones's preposition number seven:
"The general forms being first cared for, these should be subdivided and ornamented by general lines, the interstices may then be subdivided and enriched for closer inspection."
This forms a hierarchy of detail whereby the eye ascends from the least to most detailed areas. Levels which have suddenly changes of detail in this heirarchy form the interesting texture. This is why eyes are found to be focal spots on the face. Human vision first perceives the general form of the face, and then starts to recognize crude forms, the chin, nose, ears, mouth, but suddenly notes a contrastingly large amount of detail in the texture of the mouth and the iris of the eye especially in blue eyes where this texture is most visible. This focal spot here is helpful as a large amount of information of intention and emotion is contained in the eyes and mouth, and the interest given is well deserved. The studio insists on the use of glass eyes in statuary whenever possible because of this, as the texture of a glass eye far exceeds anything painted for the same price and evokes from the faithful the desired visual focus on the human emotion and mind of the saint.
Anomalousness:
The last of the purely geometric principles, anomalousness, is perhaps the most foreign to Christian usage. As it is characterized by a odd lack of a feature expected by the eye, such as a hole in a pattern, it may destroy a sense of repose in the viewer. As such, this might be construed as contrary one of Owen Jones' more quote-worthy aesthetic proposition number four, where he writes:
"True beauty result from that repose which the mind feels when the eye, the intellect, and the affections, are satisfied from the absence of any want."
The fact that it is capable of breaking this repose is exactly why it grabs focus. When used with caution, this interest grabbing phenomenon can be used with success. Here shown in the coffered ceiling of St. Mary of the Lake in Chicago, a pattern is interrupted marvelously in the shape of a cross to show the heavens and Jesus Christ as king recumbent breaking through into the space of the church. Worthy of long mediation, here the anomalous break in the expected pattern demands the interest of the eye and focuses the viewer beyond the physical bounds of the otherwise flat ceiling.
Hue:
Lastly come the three causes from color, the first and most obvious of these being hue. By hue it is meant the particular wavelength of visible light to which we prescribe a color name, red, green, blue, et cetera. A contrast of hues creates a focal spot in a very natural way to the human eye, such as the interest given to a ripe tomato hidden among its branches, versus say a tomato hornworm caterpillar among the same.
As modern American churches are often quite anemic, this effect is quite easy to employ where just about any hue is a contrast to the regular greys, browns, and beiges. At the National Shrine of the Immaculate Conception in Washington D.C., this contrast is most prominent with the church's striking blue dome.
As the church itself is mostly warm tans and reds, and blue being near the chromatic opposite of these colors, the contrast is strong and interest grabbing. If the color was a more similar hue, say a Tuscan red, this effect would evoke less interest, doubly so, as the other hue of the church at large contrasts with the dome as much as the dome to the church. This effect has been studied and explored in great depth by Goethe and Chevreul in their respective color theory treatesies, 'Zer Farbenlehre', and 'On the Simultaneous Contrast of Color'.
Brightness
Less obvious in human vision but more primitive in effect, focus spots by contrast of brightness is notable. Here focal interest is maintained merely by difference in the lightness or darkness of a given area. Now, lightness and darkness are not identical in this effect, but are symmetrical. As noted by Goethe in his forementioned work, lightness tends to have a expanding effect, while darkness a contracting one. This is to say, black details shrink the eye into them, while white details expand out toward the eye. Since no vision is possible without both light and dark, both are necessary. The mechanism of this effect lies in the degree and gradation between the two. Secular interior designers know this effect intimately, with the exact effects of brightness in architecture well known.
Here a Greek water jug further demonstrates this principle. The background in black does not invade the vision, but rather stand as a canvas for the uncolored red figure to stand on. The lighter red figures are not set on the black ground at all, but are actually an absence in the black and yet seem to emanate from the black. The white figures of Eros and Dionysus's pet panther dominate expressing themselves onto the black ground. The contrast of brightness between the red figures and the black background is less than between the white figures and the black ground so focus is placed firstly on the white. The red hue is dull, and does not compensate enough to overpower the grasp of the white. If the red was more vibrant, the red and white might be more competitive. This principle of vibrancy will be discussed next.
Vibrancy:
Vibrancy is the last of the causes of focal spots here in this article, and perhaps one of the more confusing after initial understanding due to misjudged in how the eye falsely believes to be the normal vibrancy of each color. The effect is simple, vibrancy is merely the intensity and purity of the color. Since the human eye is a color sensing organ, it inherently is sensitive to greater strength colors.
The case of the poison dart frog is a good example. The poison dart frog is a tropical animal that lives in a very busy green environment; its skin is toxic, discouraging predators, but still it is better to not be preyed upon at all and to survive predation attempts uninjured.
The strategy is this: the mottled camouflage pattern hides the body shape of the frog from and to some extent the precise location but not the presence of the frog, so when the frog is inevitably spotted, the vibrancy of the frog warns the various birds and mammals that he might not actually be that nice of a snack. This is effective despite that poison dart frogs come in a wide variety of bright colors: reds, greens, blues, yellows. This is called disruptive camouflage. Here the vibrancy of the color overpowers the contrast of hues because of the overall busy colorfulness and low contrast of texture with its environment. Systems in this way can grow to be quite sophisticated.
Further complications are at play here, as not all hues are considered equally interesting. In addition, not all hue are imagined in the same normalized vibrancy. For example, humans are prejudiced to presume yellows to be bright and browns to be dull, where a dull yellow is perceived as a sickly olive and a vibrant brown is simple orange by another name. One only has to look at a color wheel reduced to greyscale to start to see the problems here. The same is true for assumed brightness of colors, but all this is worthy as contents of its own article.
Together these principles act to direct the eye around in a way like dancing across multiple layers of abstraction. These principles can even be present all at the same time creating a beautiful play of effects leaving the view deeply interesting. With the greater depth of aesthetic value on multiple fronts, the eye may never grow bored always with more interactions to discover.
By building art and architecture with knowledge of these principles, many goods can be obtained, the least of these not being piety and devotion. Without them, our buildings and churches would only be the most most boring and unengaging, full of unhelpful distractions, and failing to facilitate active participation in the sacred mysteries.
If you are intrigued by these effects and how they influence human perception and behavior, you may appreciate our other articles on color theory: